Organic light-emitting diode (OLED) display panels have been widely used in various display devices. OLED display panels are often susceptible to oxygen and moisture, which may cause the OLEDs in the display panels to degrade. Encapsulation or packing materials are used to form encapsulation structures that seal the display panels and prevent the display panels from contacting the outside environment. Hard film layers and liquid filling materials have been used for forming encapsulation layers and structures.
In existing fabrication processes of a curved OLED display panel, external forces are often applied on a flat display panel to bend the flat display panel and keep the display panel in a curved shape. For example, a flat display panel is often placed in a curved structure such as a curved frame. The forces applied by the curved frame may keep the display panel in the properly curved shape. The easier it is to bend a display panel, the less force it is required in the fabrication process to curve the display panel. A display panel with a thin substrate and/or a thin encapsulation structure may require less force to curve. However, thin substrates are often expensive to manufacture. Thin encapsulation structures are more prone to leak moisture and oxygen.
The bending stress on a display panel often determines the structure strength of the panel. In the fabrication process of curved OLED display panels, the substrate and the encapsulation structure often critically affect the characteristics of a curved OLED display panel, such as the bending stress. Glass is commonly used as the material for the substrate of a display panel. Because the glass substrate can be considerably thick, the bending stress of the glass substrate can be high. An existing encapsulation layer may not be able to provide the bending force applied to the display panel/glass substrate. Therefore, an encapsulation structure that is easy to bend may be suitable for fabricating curved OLED display panels.